Diagnostic electrocardiographic trap: A case of conduction system pacing.

His-bundle pacing (HBP) is a relatively new method of cardiac pacing, with recent studies showing an association between HBP and a lower risk of developing right ventricular heart failure compared to classical pacing methods. However, HBP is also associated with a higher risk of lead dislodgement, undersensing, and loss of capture. As such, a detailed assessment of pacing effectiveness in pacemaker patients is vital. In the presented case, an electrocardiogram (ECG) recording seems to present successful selective His-bundle pacing, while pacemaker follow-up demonstrated the loss of ventricular capture. In conclusion, patients receiving HBP should undergo ECG alongside pacing parameter analysis and pacing electrograms, as differences in successful and unsuccessful pacing ECG can be very subtle.